An electric bicycle is a bicycle which has a rechargeable battery and driving means powered by the rechargeable battery so that the electric bicycle can be actuated by the electrical power. The rechargeable battery of the electric bicycle generally can supply power for about 30 minutes of operation of the bicycle so that a rider has to estimate his/her travel distance before he/she starts to take the bicycle trip. It is inconvenient for the rider to charge the rechargeable battery if the electric bicycle is used in a country area where the charging equipment is difficult to be found. Therefore, the rider has to charge the rechargeable battery of the electric bicycle at home before carrying the electric bicycle on his/her car to the country area where the electric bicycle is intended to be used.
The present invention provides a charging device on a vehicle which is electrically connected to the battery of the vehicle and to the rechargeable battery so that the rechargeable battery of the electric bicycle can be charged during the movement of the vehicle.